The present invention relates generally to communication systems and, in particular, to a method for determining a quantity of channel resources to reserve for data services in a communication system that supports both data and voice services.
Mobile communication systems, that once only provided voice services, are today being developed to provide voice and data services to mobile communication units. In such systems, the voice and data services can share a pool of channel resources, each service using available channel resources as needed. When voice and data services are contending for the same specific channel resources, however, priority is given to the voice services.
During periods of high voice service traffic the data services are left with few channel resources and thus become unavailable or exhibit relatively long data delays. Such degraded data service typically becomes unacceptable to users below a certain level of service. To prevent an unacceptable level of data service, channel resources are removed from the pool of common channel resources and reserved for use by data services exclusively.
Making channel resources unavailable to the voice services, however, reduces the peak voice service capacity of the communication system. Optimally, the communication system should guarantee a certain minimal level of data service while maintaining a maximum capacity for peak voice service traffic. The need for such a solution is most acute for systems with fixed channel resources, since additional channel resources may not be available for adding data services due to spectrum constraints or the required expense.
Equations for determining channel resource requirements for given voice traffic loads are known. Equations for determining channel resource requirements for data traffic loads are also known from queuing theory. The prior art is limited to addressing channel resource needs for voice services and data services separately, but not combined as these services are in today""s communication systems. Therefore, a need exists for a method for determining an optimal quantity of channel resources to reserve for data services in communication systems that support both data and voice services.